Passive sampling affecting factors

INTRODUCTION 14 PESTICIDE CATEGORIES 15 PESTICIDE HANDLERS 15 Agricultural Pesticide Handlers 15 Tasks Performed by an Individual 16 Factors Affecting Exposure 16 Residential and Institutional Pesticide Handlers 18 Families of Pesticide Handlers 19 STUDY DESIGN CONSIDERATIONS 20 Worker Stratification 21 Routes of Exposure 21 Respiratory Exposure 21 Dermal Exposure 21 Sampling Strategy Selection 21 Statistical Analysis 22 PROTECTION OF HUMAN SUBJECTS 22 PESTICIDE EXPOSURE MONITORING METHODS 23 Passive Dosimetry 23... 

An experiment in which all other relevant variables are held constant is an eflective approach when it can he achieved. However, aU relevant factors may not be known. Furthermore, circumstances often preclude the ability to hold some variables constant. For example, there may be unforeseen factors that affect the course of a corrosion experiment, as in the poleirization curves in Fig. 7 for nominally identical samples of copper (UNS C10920). Most of the curves indicate the copper will actively corrode in the solution. However, one curve indicates the copper will passivate over a narrow range of potentials. Had a structure or device been built based on the passive curve it would have failed unexpectedly. Fortunately, enough replicate curves were measured to show that the passive curve was the exception [42]. 

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